Cephalosporins having a ureido acyl side chain are disclosed in U.S. Pat. Nos. 3,673,183; 3,708,479; 3,833,568; and 3,860,591 and those also having a 7.alpha.-methoxy substituent are disclosed in U.S. Pat. Nos. 3,978,051; 3,989,693; and 3,989,697. Cephalosporins having various acyl side chains and a 7.alpha.-methoxy substituent are taught in various U.S. patents including 3,775,410; 3,780,031; 3,780,033; 3,780,034; 3,780,037; 3,843,641; etc.
Cephalosporins having an acylureido acyl side chain are disclosed in U.S. Pat. Nos. 3,687,641; 3,687,949; 3,925,368; 3,956,292; 3,954,802; and German Offenlegungsschrift No. 2,514,019.